Aero Peek is a cool new feature in Windows 7 that gives you X-Ray vision! By hovering the mouse over the small bar on the right hand side of the taskbar, you can temporarily see behind any open windows, to the desktop.Aero Peek is also used when the Alt+Tab combination on the keyboard is used & also when you hover your mouse over a Taskbar preview.By default, the delay from hovering the mouse on the bar on the Taskbar to showing the desktop is 1 second. This guide will show you how to speed things up (or slow it down).

Step 1.

Start by hitting the WinKey+R, typing regedit into the Run box and hitting OK.

Step 2.

In regedit navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced

Step 3.

In the right hand pane right click a blank space and select New > DWORD (32-bit) Value.

Name it DesktopLivePreviewHoverTime and hit Enter.

Step 4.

In the right hand pane,Double click on the new DesktopLivePreviewHoverTime entry. Under Base make sure that Decimal is checked. Under Value Data: enter the number of milliseconds you wish the delay to be. 1000 (1 second) is default. Enter a higher value to slow Aero Peek down, or choose a lower value to speed things up.